The etiology of the pruritus or itch associated with liver disease is unknown, and its current treatments are empirical and unsatisfactory. This form of pruritus can be so severe that it can be an indication for liver transplantation, in spite of adequate hepatic function. There are three lines of evidence that support the role of the endogenous opioid system in the pruritus of liver disease: (i) morphine and opiate drugs are associated with pruritus, (ii) patients with liver disease and pruritus experience an unpleasant cerebral reaction after the administration of the opiate antagonist nalmefene, suggesting that they may have increased opioidergic neurotransmission/neuromodulation in the central nervous system, (iii) the administration of nalmefene is associated with marked amelioration of their pruritus. These observations suggest that this form of pruritus is mediated at least in part by endogenous opioids in the brain. In previous studies we have shown the administration of the opiate antagonists naloxone and nalmefene is associated with amelioration of the pruritus of cholestasis and the associated scratching activity. Data obtained by quantitative methodology (by using an instrument that measures scratching behavior) revealed that scratching activity is associated with a 24-hour rhythm. Circadian rhythms are internally generated from external cues such as those related to light and darkness. Melatonin, the substance implicated in circadian rhythmicity is produced by the pineal gland and is also regulated by dark-light cycles. There are clinical anecdotes of patients with the pruritus of cholestasis who have experienced amelioration of their pruritus when they move to sunny geographical areas suggesting that more light is better for them. This clinical observation and the association between the pineal gland and the opioid system suggest that bright-light phototherapy (via the eyes) may be an effective therapy for this symptom. That is the aim of this project. If bright-light phototherapy is found to be effective in the treatment of this form of pruritus, a non-invasive therapy for this symptom will be identified. This will advance the field because patients with liver disease may have their hepatic function impaired which may be of concern when administering drugs that are metabolized in the liver. If instead of a beneficial effect, bright-light phototherapy is found to increase this form of pruritus, the role of the brain in the mediation of this symptom will be underscored. We are currently conducting a pilot study of the use of bright-light phototherapy for the pruritus of cholestasis. This pilot study will include ten patients with pruritus of cholestasis. Baseline quantitation of scratching activity and subjective assessment of pruritus by the use of a visual analogue score for pruritus is done at baseline and after 4 weeks of therapy with bright-light (10,000 lux to the eye).